As a device receiving an RF signal existing in the air inside a user terminal or transmitting a signal existing inside the user terminal to the outside, an antenna corresponds to an essential device used in wireless communication. Recently, as mobile communication terminals have become more compact and light-weight, the antenna has also been required to become slimmer. Additionally, as the amount of data being wirelessly transmitted/received has increased, antennae having more enhanced performance are also being required.
Accordingly, an antenna using ground radiation, which is included in the user terminal itself, has been proposed in order to meet such requirements. More specifically, when the antenna is configured by using a ground of the terminal itself as a portion of a radiator, the size of the radiator, which occupies the largest space within the antenna, may be reduced, thereby contributing to realizing a compact size of the antenna.
As described above, European Patent No. 1962372 corresponds to a prior art technology, which is related to a ground radiation antenna using the ground of the user terminal itself as the radiator. This patent proposes a technology for designing an antenna using a ground of a user terminal, when a body of the user terminal, such as a folder type user terminal, is configured to be divided into two sub-bodies, and when each body is configured to be connected to one another through an electrical element, such as an FPCB.
According to this patent, in a folder type user terminal having a body, which is divided into two sub-bodies, a capacitor for tuning a resonance frequency is inserted in an electric conductor for performing inductive coupling between the two sub-bodies.
Therefore, the above-described antenna shall only be used in a user terminal (e.g., folder type user terminal) being configured of two sub-bodies, and, since the electric conductor for inductive coupling is decided to have a constant length, there lie many problems in that the structure is not simple, and that the scope of devices that can be applied is also very limited.
FIG. 1 illustrates an exemplary structural view of a related art ground radiation antenna. Referring to FIG. 1, the related art ground radiation antenna (10) is equipped with a radiation structure (11) for helping (or aiding) ground radiation, as shown in FIG. 1. More specifically, the radiation structure (11) corresponds to a complex structure consisting of a dielectric substance and conduction lines. And, in order to manufacture such a complex structure, a considerable amount of fabrication cost and complex fabrication process have been required. Additionally, in addition to the radiation structure (11), the ground radiation antenna is also configured of an inductor and capacitor (12a, 12b, 12c) for impedance matching and radiation performance control.
Therefore, although the related art ground radiation antenna uses the ground as its radiator, it still requires a separate radiation structure having a complex structure. And, in order to implement such a radiation structure, a considerable amount of fabrication cost has been required. Moreover, as the radiation structure of the antenna becomes more complex, there have been limitations in creating slimmer user terminals.
Most particularly, the related art ground radiation antenna is disadvantageous in that the essential phenomenon of ground radiation was not fully nor well understood, and, accordingly, due to an unnecessarily complex structure for implementing such ground radiation, the fabrication cost has increased, and the fabrication process has become complicated.